The relationship between hypertension and plasma allantoin, uric acid, xanthine oxidase activity and nitrite, and their predictive capacity in severe preeclampsia

The Role of Xanthine Oxidase in Pregnancy Complications: A Systematic Review

Xanthine oxidoreductase (XOR) is an enzyme involved in the oxidation of hypoxanthine and xanthine to uric acid. XOR has two isoforms: xanthine dehydrogenase and xanthine oxidase (XO). XO plays a major role in oxidative stress, causing the formation of reactive oxygen species. In the present study, we aimed to summarize the evidence on the association between XO and pregnancy complications. The PRISMA checklist guided the reporting of the data. We conducted systematic searches in the PubMed and Web of Science databases to identify all human studies investigating XO in pregnancy diseases up to June 2024. A total of 195 references have been identified and 14 studies were included. Most studies focused on women with PE and GD. Overall, all the included studies found a statistically significant increase in maternal, placental, and/or fetal XO levels, activity, or tissue expression in women with pregnancy complications, compared to those with uncomplicated pregnancies. Although promising, the quality and dimension of the included studies do not allow for a definitive answer to the question of whether XO may play a crucial role in pregnancy complications. Future studies are warranted to confirm if XO could represent a prognostic and therapeutic marker in pregnancy complications and their impact on long-term maternal and offspring cardiovascular health.

Uric acid in the pathogenesis of metabolic, renal, and cardiovascular diseases: A review

The association between uric acid (UA) on one side and systemic hypertension (Htn), dyslipidemia, glucose intolerance, overweight, fatty liver, renal disease and cardiovascular disease (CVD) on the other side is well recognized. However, the causal relationship between UA and these different clinical problems is still debatable. The recent years have witnessed hundreds of experimental and clinical trials that favored the opinion that UA is a probable player in the pathogenesis of these disease entities. These studies disclosed the strong association between hyperuricemia and metabolic syndrome (MS), obesity, Htn, type 2 diabetes mellitus (DM), non-alcoholic fatty liver disease, hypertriglyceridemia, acute kidney injury, chronic kidney disease (CKD), coronary heart disease (CHD), heart failure and increased mortality among cardiac and CKD patients. The association between UA and nephrolithiasis or preeclampsia is a non-debatable association. Recent experimental trials have disclosed different changes in enzyme activities induced by UA. Nitric oxide (NO) synthase, adenosine monophosphate kinase (AMPK), adenosine monophosphate dehydrogenase (AMPD), and nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase are affected by UA. These changes in enzymatic activities can lead to the observed biochemical and pathological changes associated with UA. The recent experimental, clinical, interventional, and epidemiologic trials favor the concept of a causative role of UA in the pathogenesis of MS, renal, and CVDs.